This invention is directed generally to the dispensing of objects, and more particularly to dispensing singulated objects.
The problem of counting and dispensing a predetermined quantity from a bulk of small articles exists for a multitude of items and processes. Exemplary items include comestibles such as candies and breath mints, machine components such as bolts, nuts and other fasteners, valuables such as diamonds and other gemstones, vitamins, and the like.
The problem has been addressed using multiple approaches. For example, a cavity-filling device sized to physical particulars of a specific article is disclosed in U.S. Pat. No. 3,775,941 to Bross. As another example, a device that counts total weight using a calibrated pieceweight measurement is disclosed in U.S. Pat. No. 4,685,525 to Knothe et al. As an additional example, a device employing a vibratory feeder to singulate (and thus enable counting) is disclosed in U.S. Pat. No. 6,182,718 to Seaton. As yet another example, a device that employs a vacuum to separate and count a fixed, but predetermined number of objects is disclosed in U.S. Pat. No. 6,053,302 to Leu et al. The several devices and techniques exemplified above individually provide varying levels of performance in key operational parameters such as speed, accuracy, universality (adaptability), size, complexity, and cost. But few, if any, provide a high level of measure in more than one or two of the above parameters. Cavity fillers of the type described in Bross are typically bulky and suitable only for articles that closely match the cavity size. Vibratory counters like that disclosed in Seaton are ordinarily bulky and can be difficult to tune (i.e., configure). Weight counters like that described in Knothe can be inaccurate due to piece-weight variability. Vacuum-based systems such as that shown in Leu et al. are typically complex, slow and difficult to calibrate.
In view of the foregoing, a singulating device which is fast, accurate, small, easy to configure, reliable, and nearly universal would be desirable.
The present invention is directed to devices and methods for rapidly and accurately counting and dispensing a predetermined quantity of articles from a bulk supply of such articles. The devices include a bulk housing for storing a plurality of substantially identical articles and an exit channel. As a first aspect, a device of the present invention also includes, in the exit channel, a forwardly-directed jet aperture and a rearwardly-directed jet aperture, each of which is fluidly connected to a positive pressure source. A forwardly-directed jet generated by the positive pressure source through the forward jet aperture can accelerate singulated articles in the exit channel, thereby increasing the interval between individual articles and rendering them more easily and accurately counted. A rearwardly-directed jet generated by the positive pressure source through the rearwardly-directed jet aperture can cause articles in the exit channel to return to the housing. A controller operatively connected with the pressure source(s) selectively controls the application of positive pressure to the aforementioned apertures to induce or halt singulation of the articles; the controller may be operatively associated with a sensor that detects and counts articles passing through the exit channel.
As a second aspect of the invention, a singulating device having a bulk housing and an exit channel includes a jet aperture positioned across the bulk housing from the exit channel. The jet nozzle is fluidly connected with a positive pressure source, which in turn is connected with a controller that selectively controls the application of positive pressure through the jet aperture. This configuration can produce a jet that urges articles in the housing to travel toward the exit channel.
As a third aspect of the present invention, a singulating device having a bulk housing and an exit channel includes an article-orienting unit that has a pair of panels that, in concert with an upstream portion of the exit channel, define an entry space that permits an oblong or oblate article to enter the exit channel only in a longitudinal orientation in which the longest dimension of the article is generally parallel to a downstream flow path. The upstream ends of the panels extend upstream away from the exit channel and are spaced such that an oblong or oblate article entering the entry space in a transverse orientation in which its longest dimension is generally perpendicular to the downstream flow path that strikes the exit channel""s upstream portion and is re-oriented to the longitudinal orientation in which passage through the exit channel is permitted. In one embodiment, the panels are parallel with one another, and the articles are reoriented when striking either exposed edge of the exit channel upstream portion. In a second embodiment, a third panel perpendicular to the first two panels is included, such that the entry space is generally rectangular. In a third embodiment, the panels are hinged to one another and pivot about a pivot axis that is parallel to the direction of flow, such that the entry space (which is adjustable) is generally triangular. In any of these embodiments, the function of the panels is to orient the objects into a desired attitude for entry into the exit channel.
In singulating devices with these aspects of the invention, individual articles can enter the exit channel from the housing and travel through the exit channel in single file and with an interval sufficient to allow accurate detection and precise counting of the articles. The pneumatic, reversible nature of the device can enable the handling of a large range of sizes and shapes with a single device configuration. Furthermore, this same feature allows simple adjustments to be applied to handle an even broader range of sizes. The ability to control the various airflows permits the mechanism to be implemented in a volume not significantly larger than a small portion of the bottom of a bulk storage chamber.